Heating device for incubators



Nov- 10, 1925.

W. ESHELMAN HEATING DEVICE FOR INCUBATORS Filed July l0, 1923 Patented Nov. 10, 192.5.

WILLIS ESHELMAN, 0F LAMPETER, PENNSYLVANIA.

HEATING DEVICE FOR INCUBA'IORS.

Application led July 10, 1923. Serial N0. 650,664.

To all whom t may concern.'

Be it known that I, WILLIS ESHELMAN, a citizen of the United States, residing in Lampeter, Pennsylvania, have invented a Heating Device for Incubators, of which the following is a specification.

One object of this invention is to provide a device of the utmost simplicity and safety for supplying the heat necessary to maintain an incubator at a substantially constant temperature, and said invention more especially contemplates a combination of apparatus involving electric lamps arranged in a novel manner for accomplishing the desired results.

Another object of, the invention is to provide electrical heating means including a constant and a variable source of heat and thermostatic means whereby the operation of the variable heating source is controlled.

These objects and other advantageous ends I attain as hereinafter set forth, reference being had to the accompanying drawings, in which,

Fig. 1 is a vertical section, to some extent diagrammatic, illustrating the preferred form of apparatus constituting my invention; and,

Fig. 2 is an inverted plan of the lamp casing.

In the above drawings, l represents one end of an incubator which may be of any desired construction and which has an opening 2 adjacent its top for the inlet of. heated air. It may also have an opening 3 in its lower portion for the outlet of cooled air.

Supported in any suitable manner preferably from the incubator 1, is a vertically extending and substantially cylindrical casing 4 open at the bot-tom and closed at its to where it is connected to the hot air inlet opening 2 of the incubator. This casing is preferably made of sheet metal surrounded by or lined as may be desired, with sheet asbestos or other heat insulating material. Extending coaxially within the casing 4 and spaced away from the walls thereof is a corrugated sheet metal sleeve 5 whose bottom is substantially flush with the bottom of the casing l and whose upper end terminates at or slightly below the level of the opening 2 of the incubator. Within the sleeve 5 is removably mounted a vertically extending metal frame 6-6 including a bottom member and two substantially lower ends are similarly bolted to a second lamp socket 8. The frame is of such dlmenslons that an incandescent electric lamp 9 may be mounted in the socket 8 and a second incandescent lamp 10 in the socket 7,-the heating unit thus formed being removably retained within the sleeve 5 by a cross bar 11 pivoted at 12 to one side of the casing 4 and extending under the frame 6-6 so that its :free end may be engaged at will with a hook 13 projecting from the casing 4 opposite the pivot 12. When disengaged from the hook said bar may be swung to one side so as to permit of the frame 6 6 with the two lamp sockets and the lamps therein being drawn out of the sleeve 5 for replacement or ins ection.

The incubator 1 is equippe with any desired form of thermostat (not shown) but including a cont-rolling b ar 14 extending over its top 15 and operative upon a spring or other suitable contact 16. The latter at one end is connected to the top 15 of the incubator by a screw 17 and its opposite free end projects over a fixed contact 18 in such manner that when the temperature in the incubator falls below a predetermined point, the bar 14 causes it to be engaged by a spring contact 16. On the other hand, when the temperature in the incubator rises above the predetermined fixed upper limit, the thermostat bar 14 swings upwardly and thereby causes or permits the spring contact 16 to disengage the fixed contact 18.

In accordance with my invention, one of the lamps, as the lower lamp 9 is connected permanently in circuit with a suitable cur` rent source so that it is lighted at all times. On the other hand, the lamp 10 is connected in circuit with the contacts 16 and 18 s0 that it is lighted only when the temperature of the incubator is below the desired point. As a result of the abo-ve arrangement of parts, cold air rises through the corrugated sleeve 5 around the lamps and also between said sleeve and the inner wall of the casing 4 from the top of which it flows into the incubator through the opening 2. The heating capacity of the lamp 9 1s such that it causes such a supply of hot air to the incubator as is almost sufficient to maintain it at the desired temperature. When, however, because of changes of weather or for any other reason, the temperature of the incubator falls so that more heat is required to maintain it at the desired point, the thermostat acts through the bar 14 to close the contacts 16 and 18, thus throwing into circuit the second lamp 10 which is of such heating capacity as to be capable of raising the incubator to and maintaining it at any dcsired temperature under the most extreme conditions. IVhen, however, the incubator temperature rises above lthe predetermined point, the action of the thermostat causes the terminals 16-18 to be separated and thus cuts the lamp 10 out of service.

From the above description, it will be appreciated that my heating device is of the utmost simplicity and is capable of operating for long periods of time without attention. It is moreover in the highest degree free -from all danger of fire and is of such a nature as will maintain the temperature of theincubator substantially constant under conditions of operation.

I claim:

1. The combination 'with an incubator of a casing supplemental to the incubator having a chamber adapted to be connected thereto; two separate heating means in said chamber; and thermostatic means responsive to the temperature of the incubator for controlling the supply of current to one of said heating means to the exclusion of the other.

2. The combination with an incubator of a casing supplemental to the incubator having a chamber adapted to be connected thereto; a plurality ot' lamps in said chamber of which one is permanently supplied with current; and temperature responsive means for governing the current How to another lamp in accordance with temperature variations in the incubator.

3. A heating device for incubators, comprising a plurality of electric heating elements located outside of the incubator and arranged one aboveianother, and a casing having walls closely surrounding the said elements but with spaces left for the passage of air, the said walls forming an air duct which is open at its lower end and which is adapted to be connected at its upper end to deliver air to the interior of the incubator.

4t. The combination with an incubator of a vertically extending casing supplemental to the p incubator and having a chamber therein open at its lower end and at its upper end adapted to be connected to deliver air to the incubator; an incandescent lamp for heating the air in said casing; and thermostatically controlled switch for governing the flow of current to said lamp.

5. A heating device for incubators, comprising two incandescent lamps located outside of the incubator and arranged one above the other, a casing having walls closely surrounding the said lamps but with spaces left for the passage of air, the said walls forming an air -duct which is open at its lower end and which is adapted to be connected at its upper end to deliver air to the interior of the incubator, and a thermostatically controlled switch for regulating the flow of current to one of the said lamps independently of the other.'

6. A heating device for incubators, comprising a casing supplemental to the incubator and having a chamber open at one end and adapted to be connected with the interior of an incubator at the other end, two electric heating elements in the casing past which air must move successively to reach the incubator, and a frame movably connected in the casing and carrying both of the heating elements.

7 The combination with an incubator of a vertically extending casing connected .to deliver heated air thereto; a sleeve mounted in the casing and spaced away from the walls thereof; a frame removably mounted in said sleeve; and at least one heating element carried by said frame.

t3. A heating device for incubators, comprising two incandescent lamps located outside of the incubator and arranged one above the other, a casing having walls closely surrounding the said lamps but with spaces left for the passage of air, the said walls forming an air duct which is open at its lower end and which is adapted to be connected at its upper end to deliver air to the interior of the incubator, and a frame movably mounted in the said casing and carrying both of the said lamps.

9. A heating device for incubators comprising a vertically extending casing connected to deliver heated air thereto; a sleeve mounted in said casing; a frame removably'mounted in said sleeve; a plurality of lamp sockets carried by said frame; and electric lamps mounted in said sockets.

WILLIS ESHELMAN. 

